#include <stdio.h>
#include <stdlib.h>

#define SUB(x,y) x-y
#define ACCESS_BEFORE(element, offset, value) *SUB(&element, offset) =value

int main()
{
    int i;
    int k;
    int array[10] = {1,2,3,4,5,6,7,8,9,10};
    k = ACCESS_BEFORE(array[5], 4, 6);
    for (i = 0; i<10; ++i){printf("%d", array[i]);}
    return 0;
}
